ecs: Make service a parent of task

[ekimekim]

Fixes #2041

[2opremio]

Did you test it in the UI?

[ekimekim]

not yet

[2opremio]

We may need to modify the rendering code for service parents to show on the details panel (I am not sure).

[2opremio]

I at least expect #2040 to require changes in rendering.

[ekimekim]

Turns out the render code already does this implicitly, which is fine for now.
I may come back to this branch to remove that special-case and do it in the report properly, instead.

[2opremio]

@ekimekim ping

[2opremio]

@ekimekim re-ping :)

[ekimekim]

Closing in favor of #2436, since this is required for that and it's easier than stacking PRs on each other.